Weighing scale



FIG. 1 is a top plan view of a weighing scale, showing my new design;

FIG. 2 is a front-elevational view thereof;

FIG. 3 is a bottom-plan view thereof;

FIG. 4 is a rear-elevational view thereof; and

FIG. 5 is a side-elevational view thereof. 

The ornamental design for a weighing scale, as shown. 